Group C, as a "mixed class".
Group C has been done here before, an alien in the short tail will be about 6 seconds of a lap faster. the Mazda with a midfielder
will be struggling against a long tail or short tail with a midfielder, but with the disadvantage of the long straight, as will the short tail.
Once the long tail is in front, then overtaking is close to impossible.
if the midfielder gets a long tail or merc in front from the start, highly likely, then the fastest short tail will have an almost impossible task of getting by.
That assumes that these can be kept on the road for 45minuits, the short tail is more like an overpowered gt3 with attitude, certainly the most stable of all these cars.
The Mercedes is the joker in the pack, if you can keep it going for most of the circuit, then nothing can touch it on the long straight, or any straight you try and overtake it on, good luck with that.
For a championship, where selecting just one car for all circuits will make for interesting racing, some may just find these cars hard to live with, that is the advantage of the short tail, where that leaves the Mazda is somewhat perplexing, perhaps you could give that car ABS and TC.
PS
with "normals"
driving, all 4 give the same lap time, when aliens are involved, then times can be all over the place.
